This invention relates to a disposal device for evaporation disposal of waste liquor generated as by developing processing of a photographic light-sensitive material, by The invention refers to a device for use with automatic developing machine for photography (hereinafter abbreviated to as "photographic processing waste liquor" or "waste liquor"), particularly to a disposal device for photographic processing waste liquor suitable for disposal as arranged with an automatic developing machine or in the vicinity of an automatic developing machine.
Generally speaking, photographic processing of a light-sensitive silver halide photographic material has been performed by combining the steps by use of processing liquors having one or more of the functions such as developing, fixing, water washing, etc. in the case of black-and-white light-sensitive materials, and color developing, bleach-fixing (or bleaching and fixing), water washing, stabilizing, etc. in the case of color light-sensitive material.
In photographic processing in which a large amount of light-sensitive materials are processed, the components consumed by processing are supplemented, while the components thickened dissolution or evaporation in the processing liquor by processing (e.g. bromide ion in a developing solution, or silver complexes in a fixing solution) are removed to maintain the components in the processing liquor at constant levels. According to such means, supplementing solutions are supplemented into the processing liquors, and a part of the processing liquors are discharged for removal of the thickened components in the photographic processing.
In recent years, there is a trend in which the amount supplemented of solutions including washing water which is supplementing liquid for water washing is reduced to great extent for the reasons in pollution or economy, but photographic processing waste liquor is led through a waste liquor pipe from the processing tank of the automatic developing machine, and diluted with waste water of washing water or cooling water of the automatic developing machine before being discarded into sewage, etc.
However, due to strengthened pollution regulation in recent years, although discarding of washing water or cooling water into sewage or rivers may be possible, discarding of photographic processing liquors other than these [e.g. developing solution, fixing solution, color developing solution, bleach-fixing solution (or bleaching solution and fixing solution), stabilizing solution, etc.] is substantially practically impossible. For these reasons, the respective photographic processing dealers are using to professional waste liquor disposal dealers for recovery of waste liquor with recovery fee or have pollution disposal equipments installed. However, using waste liquor dealers requires considerable space for storage of waste liquor, and it is very expensive in cost. Further, the pollution disposal equipment is extremely large in initial cost, and also considerable vast place is required for installation to disadvantage.
Accordingly, waste liquor is generally recovered by waste liquor recovery dealers to be detoxified by secondary and tertiary disposal. However, the waste liquor receipt price is not only becoming higher year by year due to increased recovery fee, but also due to poor recovery efficiency in mini-laboratories, etc., recovery order can be responded to with difficulty, whereby there ensues such problem that waste liquors are filled in the store, etc.
For solving these problems, for the purpose of effecting disposal of photographic processing waste liquor easily in mini-laboratories, etc., studies have been made to evaporate water and then dry or solidify suspended component of the photographic processing waste liquor by heating, as disclosed in Japanese Provisional Utility Model Publication No. 70841/1985.
Whereas, in the case of evaporation concentration of photographic processing waste liquor, the properties of the precipitates will change with progress of evaporation concentration whereby the precipitates will lose fluidity to be discharged from the processing section with difficulty. Accordingly, one may consider to set the processing time for evaporation concentration by metering photographic processing waste liquor, etc., but the working to meter the amount and set the processing time depending on the respective processing volume is cumbersome.
Accordingly, means for detecting the change in properties of the precipitates by evaporation concentration easily have been variously studied, and consequently it has been found that specific sulfur type compounds frequently used in fixing solution or bleach-fixing solution contained in photographic processing waste liquor by evaporation concentration, for example, thiosulfates or sulfites are decomposed to change the properties of the precipitates, whereby fluidity is lost, and also sulfurous acid gas, hydrogen sulfide gas are generated. Accordingly, by detecting the gas concentration generated by evaporation concentration, thereby stopping evaporation concentration, there can be obtained precipitates which can be easily taken out.